2.11 In vivo wound closure assay
C57BL/6 male mice were anesthetized by intraperitoneal injection of 4%
chloral hydrate. The skin hair on the backs of mice was removed using a
shaving machine and depilatory creams. Alcohol was used to rinse the
skin, and silicone rings with an internal diameter of 8 mm and thickness
of 0.5 mm were stitched on the skin. Two full-thickness wounds per mice
were made on the dorsal skin with surgical scissors. After surgery, the
wounds were treated with 10 μL FGF2 or PEG-FGF2 conjugates (10
μg·ml-1, produced by Wenzhou Medical University gene
engineering laboratory) or PBS once a day. Digital photographs of the
wound area were taken on days 0, 3, 5, and 7 and the wound areas were
measured using ImageJ software. The ratio of wound healing was defined
as the ratio of (the original wound area - the wound area on the
collected day) to the original wound area. Skin wound samples were
collected 7 days after injury and fixed in 4% paraformaldehyde for
histological and immunofluorescence analyses.